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Photo Forum / Film Photography / Darkroom / January 2005test strips for large enlargements
Again, wanting to do larger size prints, I need to tackle the idea of test strips for exposure. Having priced 16"x20" paper and keeping in mind that this is just a hobby for me, I'd like to reduce my cost as much as is reasonable without being a complete cheapskate. My idea is that if I buy 16"x20" (my target size) paper in the same brand and style as I am currently using in 8"x10", then I should be able to do the following sequence :: 1) cut my 8"x10" into four 4"x5" parts 2) set up my enlarger so that it is focussed and prepared including the having the 16"x20" easel ready to load with the final print sheet 3) set a piece of the 4"x5" paper into a critical area of the print and hold it down with a temporary weight (doesn't have to be fancy) 4) make my test strips on the 4"x5" pieces - hopefully, four pieces should be enough, so one 8"x10" sheet will suffice Then, having decided what my ideal exposures and aperture settings are, 6) place the 16"x20" sheet into the easel and make what will hopefully be the final print My idea is that the papers should be almost identical and as long as the placement of the easel and the enlarger settings remain constant, then exposing a bigger or smaller piece for test purposes shouldn't make any difference. Any thoughts?  Signatureregards from :: John Bartley 43 Norway Spruce Street Stittsville, Ontario Canada, K2S1P5 ( If you slow down it takes longer - does that apply to life also?) > Again, wanting to do larger size prints, I need to tackle the idea of > test strips for exposure. Having priced 16"x20" paper and keeping in [quoted text clipped - 26 lines] > > Any thoughts? There _might_ be variations from one size paper to another, even in the same brand/type/style. Then again, there might not in the paper that you buy! I would cut down the 16x20 sheet into test print sizes. Additionally, I would not go all the way down to 4x5 test prints for 16x20; I would use 5x8 or 8x10 for test prints, depending on the subject neg. Ken Hart There will be variance in batch to batch both with process and with age. Better to test out of the same box. Sometimes a 2x16 is what you really want. I think one sacrificial sheet in a ten sheet pack or 2-3 in a 50 sounds about right. That's 10% or less, pretty good if you can keep your darkroom "sacrifices" to that ratio. Signaturedarkroommike ---------- > > > Again, wanting to do larger size prints, I need to tackle the idea of [quoted text clipped - 35 lines] > > Ken Hart >Again, wanting to do larger size prints, I need to tackle the idea of >test strips for exposure. Having priced 16"x20" paper and keeping in [quoted text clipped - 26 lines] > >Any thoughts? I don't even bother to cut the paper, just rip it into strips. ... >I don't even bother to cut the paper, just rip it into strips. jan705 from Lloyd Erlick, You must have proper humidity in your darkroom! If I did that without my trusty humidifier, I'd have specks on my prints. I'd advise doing all cutting or ripping of paper at a distance from the enlarger. In fact, I'd advise making the to-be-test-strips all at once, from one sheet, and storing them in a separate bag within the package of large sheets. regards, --le Signature________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: portrait@heylloyd.com net: www.heylloyd.com ________________________________ On 1/7/2005 5:10 AM Lloyd Usenet-Erlick spake thus: >> I don't even bother to cut the paper, just rip it into strips. > [quoted text clipped - 5 lines] > one sheet, and storing them in a separate bag within > the package of large sheets. That's what I do: I keep a paper package just for test strips, prepare a bunch at once (using my trusty paper trimmer) in various sizes. Then just reach in and grab the size piece I need. SignatureToday's bullshit job description: • Collaborate to produce operational procedures for the systems management of the production Information Technology infrastructure. - from an actual job listing on Craigslist (http://www.craigslist.org) On Fri, 07 Jan 2005 06:02:43 -0600, McLeod wrote: > You must have proper humidity in your darkroom! How can one have low humidity in a room with large open trays of liquid and running water? > On Fri, 07 Jan 2005 06:02:43 -0600, McLeod wrote: > >> You must have proper humidity in your darkroom! > > How can one have low humidity in a room with large open trays of liquid > and running water? Proper ventilation. Behind my 190cm sink I have a duct running to a 125cm (5") variable speed exhaust fan to the outside. In this duct I have 8 vents about 5cm above the sink lip. Works great. I also have a hygro/thermometer mounted above the sink line to assure I keep a balance between bearable and too high/low humidity. Runs between 50 and 60% even during the summer. Right now (I just turned around and looked) it's at 55% - 21C. >> On Fri, 07 Jan 2005 06:02:43 -0600, McLeod wrote: >> [quoted text clipped - 9 lines] >too high/low humidity. Runs between 50 and 60% even during the summer. >Right now (I just turned around and looked) it's at 55% - 21C. jan805 from Lloyd Erlick, Where I live, a line of open trays would have very little effect. Even a humidifier next to the enlarger can't raise the whole room above fifty per cent relative humidity in the winter (dry season...). A device to give the darkroom worker a readout of relative humidity is invaluable. RC paper is a great way to judge the humidity - it will lie pretty close to flat under the enlarger at around 50%. If the room is too dry the paper will curl visibly toward the photosensitive coating side. Too dry, and it arches around the other way. To watch it happen before your eyes, or at least nose, breathe gently on a corner of a sheet laid out on a flat surface like and easel or enlarger baseboard. This works best if the room is very dry, so the full 'travel' can be seen. Dry powder chemicals can absorb moisture, lenses and camera bodies and gear can develop fungus, stored finished prints can mildew, human mucous membranes hurt in excessive dryness -- all point to controlling (or at least monitoring) the relative humidity in one's darkroom. regards, --le Signature________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: portrait@heylloyd.com net: www.heylloyd.com ________________________________ >If the room is too dry the paper will curl visibly >toward the photosensitive coating side. Too dry, and it >arches around the other way. jan1005 from Lloyd Erlick, In my earlier post, I made the above statement, which is incorrect. It should read as follows: ---- If the room is too dry the paper will curl visibly toward the photosensitive coating side. Too humid, and it arches around the other way. ---- There is a fortune waiting for the writer of the spell checker that knows what you mean ... (such as for instance, a spell checker might be suitable for Harry Potter and his girlfriend [girl friend? girl-friend?], whereas I would like a spelling checker ...). regards, --le Signature________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: portrait@heylloyd.com net: www.heylloyd.com ________________________________ -- > If the room is too dry the paper will curl visibly > toward the photosensitive coating side. Too humid, and > it arches around the other way. That's what happens here, until last night: This morning I took a set of FB prints off an Arkay flat-bed drier (started last night, set on low, 30 min timer, emulsion to the belt) and they came out image side convex. A lot convex. Never happened before and the humidity is low ... I'm going to soak them in Pakosol and try again. Chalk it up to general perversity. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ >Again, wanting to do larger size prints, I need to tackle the idea of >test strips for exposure. Having priced 16"x20" paper and keeping in [quoted text clipped - 26 lines] > >Any thoughts? jan705 from Lloyd Erlick, Using sheets from a different package may be a problem. Unless it is from the same production batch, there could be small differences that result in small but significant exposure differences. I'd say it's better to sacrifice one of the sheets of larger paper to have test strips from the same material. This means it's best to buy paper in the largest size package possible, so the proportion of sheets used for test strips is relatively small. (It's also best from a unit cost perspective.) regards, --le Signature________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: portrait@heylloyd.com net: www.heylloyd.com ________________________________ >Again, wanting to do larger size prints, I need to tackle the idea of >test strips for exposure. Having priced 16"x20" paper and keeping in [quoted text clipped - 3 lines] >as I am currently using in 8"x10", then I should be able to do the >following sequence :: This ought to work. What I generally do is this, I work with 8x10 paper to figure out the exposure, contrast, dodging/burning etc that I want to get the image that I want. I then use an Ilford EM-10, set it on the easel, in a place on the image with a mid-tone and turn the dial until you get a green light. Now move the enlarger head up and focus on the 16 x 20 easel, then put the EM-10 on the same part of the image that was used for the 8 x 10, and open the lens aperture until the light goes green. Then do the same thing that you did with the 8x10 - cuts way down on the number of 16 x 20 sheets that you use before you get an image that you like. > Again, wanting to do larger size prints, Thanks for the many great replies guys!!! It'll be a big help to me. Next I'll think a bit and stew on these thought of yours, then head out for paper etc. cheers Signatureregards from :: John Bartley 43 Norway Spruce Street Stittsville, Ontario Canada, K2S1P5 ( If you slow down it takes longer - does that apply to life also?) It is just plain better to cut up the 16x20" paper. Sure, you might find the lot (batch) number on the box and try to match it with some smaller paper, but I truly doubt you will find a match. When making very large prints for the first time, guestimating exposure for test strips can seem daunting. I suggest you use 'F-Stop' times to get the gross times. Here's another thought, the way I do it. I make an 8x10 workup print, doing all the burning and dodging, bleaching, etc. until I'm happy with the final product. With a little practice I don't waste much 8x10 paper doing this. Then I set up the 16x20 easel and frame the larger print in the same way, crank in the same filter setting, and finally open up the lens 1.5 stops (I had to test strip this a bit to get this setting but it remains the same from neg to neg). I often nail the 16x20 on the first try but rarely have more than one or two hit the bin until I get what I want. Of course, I use the same brand and style of paper in moving from the small to the large size. Art >It is just plain better to cut up the 16x20" paper. Sure, you might find the >lot (batch) number on the box and try to match it with some smaller paper, [quoted text clipped - 3 lines] >test strips can seem daunting. I suggest you use 'F-Stop' times to get the >gross times. >Subject: test strips for large enlargements >From: John Bartley oldrad@sympatico.ca I set up exactly as you have described, but in addition, I have an 8X10 Jobo test printer* that has barn doors and makes four, 4X5 test prints on one piece of 8X10 and normally expose each sheet @ 5, 10, 15, and 20 sec. etc. After working out the basic exposure, I go on and work out the VC settings on subsequent pieces 8X10 paper. I then expose a whole sheet of 8X10 on what I have perceived as the most important part of the photo, then develop the 8X10 dry it and evaluate this photo in lighting similar to the lighting where it will be displayed. After it's all said and done I will go on and read the exposure with my EM-10 and record the paper settings on the paper envelope or box for future reference. Quite honestly, I normally use 3 or 4 sheets of 8X10's for each 16X20. Regards. Bob McCarthy theyankeesnapper *available new (60.00) or on Ebay at around $15-30.00 USD. Wish I had one in 11X14. With test strips I'm more concerned about coverage than anything else. The goal of a test strip is, for me, to cover enough area to provide a sampling of the tonal variations of the result. So I make them 1" wide for the width of the sheet. This makes them long enough to be held down by the easel. As needed I'll use two to get the needed information. What they don't do for me is take the place of *all* exposure variations. They let me get really close very quicly. Then I'll do two or three full-size to get what I really want. Because there comes apoint where strips are useless and to continue using them is also a waste. My net benefit here is that I can compose on the easel and leave it stationary during and after the test strip process. So from a box of 50 I'll usually only need to cut up one or two sheets. Collin anyone4tennis@hotmail.com wrote: > Again, wanting to do larger size prints, I need to tackle the idea of > test strips for exposure. Having priced 16"x20" paper and keeping in [quoted text clipped - 24 lines] > exposing a bigger or smaller piece for test purposes shouldn't make any > difference. I'd suggest getting some really thick card (2 or 3mm) or thin plywood. Chop out a frame slightly smaller than 10x8 or 7x5. Then cut out rectangles for card about 22-25mm wide, giving you 5 strips on the 7x5 or 8 on 10x8. Cover all but one strip & expose. Remove another strip and expose etc. |
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